Ping_loop arguments list inconsistency

[EvelynOtero]

There are three routines "ping_loop" types in comm_mpi.f and the number of arguments is inconsistent for ping_loop1 and ping_loop2.
It gives compilation errors with Intel compiler.

The other question is argument list for ping_loop
subroutine ping_loop(t1,t0,len,nloop,nodea,nodeb,nid,x1,y1,x2,y2)
which is referenced
call ping_loop (t1,t0,len,nloop,nodea,nodeb,nid,x,y,x,y)
with x1=x2 and y1=y2. Is it intentional? It seems that fortran does not recommend this type of operations.

[stgeke]

@fischer1 Can you take care of this?

[fischer1]

resolved in #123